Surface phagocytosis of Trypanosoma brucei

554

CORRESPONDENCE

Oliver-Gonzalez, J. (1954). Anti-egg precipitins in the serum of human infected with Schistosoma mansoni. Journal

of Infectious

Diseases, 95, 86-91.

Pellegrino, J. 81 Andrade, F. 0. (1962). A rea@o peri-ovular no diagn6stico da esquistossomose mans6nica. Rev& do Znstituto -de Medicina Tropicale de Sdo Paulo, 4, 163-169.

Papua New Guinea. American Medicine

for publication

19th May,

infection associated with acute infantile disease in Pavua New Guinea SIR-KELLY & VOGE (1973) and KELLY et al. (1976) reported heavy infections of a Strongyloides species close to S. fuelleborni in a large proportion of people in the Kiunga district of Western Province of Papua New Guinea. Pathogenic infections with this parasite are unknown in this country. A syndrome has been recognized informally since 1970 in infants, aged around six weeks, in the foothills north of Kerema, 500 km from Kiunga. This syndrome is characterized by gross abdominal distension, due both to ascites and intra-intestinal gas, by peripheral oedema and by marked respiratory distress. Although the patients, approximately 20 of whom are said to have died in the first half of 1977, were known to have had “heavy hookworm” infections, the aetiology of the disease, which was almost invariably fatal, was unknown. Stools from three infants suffering from this “Swollen Belly Syndrome” were seen in September -October 1977. All three contained enormous numbers of helminth eggs, closely resembling those described by Kelly, measuring 50 pm by 35 pm and containing partially developed larvae when passed. Larvae cultured from these stools were very similar to those described for Strongytoides ftrelleborni.

While the first infant, whose infection was diagnosed very late, died, the other two responded to thiabendazole treatment and recovered. The relationshin between “Swollen Bellv and S;rongyloides infection, and the Syndrome” reasons for such massive infections in young infants are being actively investigated. We are, etc., R. W. ASHFORD J. D. VINCE M. J. GRATTEN W. E. MILES Department of Pathology, University of Papua New Guinea, P.O. Box 5623, Boroko, Papua New Guinea

and Department of Health, Free Mail Bag, Boroko, Papua New Guinea

References Little, M. D. & Voge, M. (1976). Strongyloides fulleborni-like infections in man in A.,

of Tropical

for

publication

19th

May,

1978.

1978.

Strongyloides

Kelly,

Journal 25. 694-699.

Kelly, A. & Voge,-M. (L973j. Report of a nematode found in humans at Kiunga, Western District. Papua New Guinea MedicalJournal, 16, 59.

Accepted Accepted

and Hygiene.

Surface phagocytosis of Trypanosoma brucei Sn+--Phagocytosis of encapsulated bacteria can be achieved in the absence of opsonizing antibody providing that a suitable substrate is present (WOOD, 1960). Under normal conditions leucocytes move freely in the tissues but, following injury, tend to attach to the walls of the body-cavity and other surfaces (EBERT & GRANT, 1974). Experimental Trypanosoma brucei infections are characterized by chronic inflammatory reactions with an alteration in the apparent “stickiness” of leucocytes which adhere to vascular endothelium. These mononuclear cells have been shown to be phagocytic (GOODWIN, 1971). A number of different surfaces were examined for their ability to support phagocytic activity. A 200 ~1 suspension of-washed and separated T. brucei strain 427 (concentration 3.2 X lo%-t) (LANHAM, 1968) was evenly distributed over the various surfaces to be examined. Following incubation at 37°C for 15 min, an equal volume of mouse peritoneal exudate cells (PEC) (concentration 2.0 x 106ml-1) was similarly added, and each preparation re-incubated at 37°C for 15 min. Impression smears were taken on glass coverslips smeared with 109; bovine serum albumin and the number of attached or partially engulfed trypanosomes was counted. The results are presented in the table. High values were obtained using fresh mouse tissue surface (liver and suleen) and fibrin clots. The number of parasites attached fell slightly when the tissues were boiled. This may have been due to morphological alterations to the surfaces or to destruction of naturally occurring opsonizing tissue antibodies. Few attachments were recorded on glass, bovine serum albumin or filter paper. Tissue surfaces appear capable of promoting the attachment of trypanosomes to mouse PEC in the absence of specific antibody. This may well be dependent upon the correct physical properties of the supporting substrate as well as the size and motility of the effector cells and the trypanosomes. The phenomenon of surface phagocytosis may be of significance in the disease process itself by facilitating the local trapping and subsequent removal of trypanosomes before the appearance of specific opsonizing antibodies. Additionally, it may be an important mechanism in tissue spaces where antibody concentrations may be too low to permit effective sensitization of macrophages. This process

CORRESPONDENCE

could also contribute to the local inflammation as a result of the selective release of hydrolytic enzymes from stimulated macrophages. I am, etc., R. M. COOK* Department of Zoology and Applied Entomology, Imperial College of Science and Technology, London, SW7 2AZ

* Present address : Beecham Pharmaceuticals Research Division, Brockham Park, Betchworth, Surrey, RH3 7AJ. Table Number of parasites attached per 100 PEC(‘j

Test Surface Glass 10 sU Bovine Serum Albumin Filter Paper Liver Spleen Boiled Liver Boiled Spleen Fibrin Layer

2.3

1.8 14.9 160.0 185.6 103.6 129.2 154.5

I

0.3

It 0.7 * 1.1 1 1O.O(z) 1~ 5.0(2) > 6.0t2) X. 0.7(“, ._. 7.7(“)

Coverslips were stained with Giemsa and between 200 and 500 mononuclear cells were counted per preparation. (I) Mean I~ standard error of 5 replicates. (*) Significantly different compared to glass; determined by Student’s ‘t’ test. (P
of

Tropical

Medicine

and

Hygiene,

65,

Lanham, S. M. (1968). Separation of trypanosomes from the blood of infected rats and mice bv anion exchangers. Nature, 218, 1273-1274. Wood, W. B. (1960). Phagocytosis, with particular reference to encapsulated bacteria. Bacteriological Reviews, 24, 41-49.

Accepted

for publication

16th May,

1978.

An autochthonous case of kala-azar in Libya Sra-Although there are known foci of cutaneous

555

leishmaniasis in Libya (KADIKI & ASHRAF, 1971; ASHFORD et al., 1976), we know of no reports of confirmed cases of visceral leishmaniasis from this part of the world. FRANCHINI (1932) mentioned cases of leishmaniasis but not the type of the disease. KADIKI & FAROOQ (personal communication) saw two cases of infantile kala-azar in a Benghazi hospital in 1967 but, again, the diagnosis was based on the clinical presentation. The present case is a 2:-year-old boy from Raima.a small village some 35 km south of Benghazi. He was first refer&d to the paediatric hospitai with a three-month history of recurrent loose stools and vomiting. When admitted, he had a temperature of 38.2”C with cough and pallor. The abdomen was distended with marked hepatosplenomegaly. The heart was also enlarged. Hb was 5*5-g/100 ml, WBC 4.0 x 103/mm3; neutroohils 26%; eosinophils 2 y0 ; lymphocytes 68 y(, ; monocytes 4 ‘X ; and a platelet count of 91 x 103/mm3. A bone-marrow biopsy showed hypercellular, erythroid hyperplasia. The tentative diagnosis was hypoplastic anaemia, pancytopenia, with axillary lymphadenopathy. The child was maintained on folic acid, B,, and antibiotics, and blood transfusions were given for about 35 days when the Hb had improved to 9.2 g/l00 ml and ESR was down to 80 mm. The patient was discharged. He was re-admitted about two months later, again with a puffy face and cachexia. The abdomen was fully distended, shining with tense skin and venous prominency. There was fluid thrill and ascites. The temperature was very irregular, varying from normal to 39°C. His Hb was do;;? i-20 ;/ RBC 1.4 x 106/mm3; 100 ml; 103/mm3; neutrophils 18”,,, ; lymphocytes 80 yb ; and monocytes 2 “,,. ESR was up to 160 mm and the albumin/globulin ratio was 1:6. The red cells appeared anisocytotic, poikilocytotic and hypochromic. A second bone-marrow aspirate was taken. It showed hyperplasia with numerous histiocytes with Leishman-Donovan bodies in their cytoplasm. The diagnosis was confirmed by inoculating the bonemarrow aspirate into NNN culture media, the cultures showing profuse promastigote growth on the third day. Blood cultures in the same medium remained negative. Sadly, the child has since died of complications (measles). We feel that this first autochthonous case of kala-azar in Libya may be only the tip of the iceberg. All the conditions are right for the transmission of the disease and, indeed, two recent deaths in the same paediatric hospital could, on clinical grounds, have been due to kala-azar. PATANE (1928) reported the presence of Phlebotomus papatasi and P. perniciosus in Benghazi, and ASHFORD et al. (1977) found P. papatasi, 1’. longicuspis and P. sergenti in the Bir Ayad area. Stray dogs are common and an Italian survey in 1925-26 found two of 117 dogs positive in Cyrenaica and nine of 638 dogs positive in Tripolitania (KADIKI & ASHRAF, 1971). LEWIS (1971) states that fly biting activity is optimal between 25 and 28°C. The case reported here probably acquired the infection some time during the summer of 1977 when the temperatures were around 26°C in the present disease focus. We have